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Vibration-assisted Surface TexturingYanjie Yuan, Jian Cao, Kornel Ehmann

Outline• Introduction and Motivation• Types of Vibration-assisted Cutting and Texturing• 1D Methods• Resonant Mode Surface Texturing • Non-resonant Mode Surface Texturing • Conclusion

that never get icy…

that inhibit fouling …

that increase heat exchange rates by 10X …

that never “wear”…

1998, 2005 and 2007 ice storm in NE of US, each cost about $4-6B

Billions of $ in loss of productivity in agriculture and $56M fuel cost for US destroyers only

95% electricity in the US is generated by steam engines; a slight efficiency increase can make a huge impact.

1/3 of energy consumption in mechanical systems is to overcome friction and replace worn materials.

Motivation – Imagine Surfaces:

Surface wettability controlling [2] Cell Culturing [1] Optics [3]

Tribology [4]

[1] Wang Y, Yu Z, Mei D, et al. Fabrication of Micro-wavy Patterned Surfaces for EnhancedCell Culturing. Procedia CIRP, 2017, 65: 279-283.

[2] Lu Y, Guo P, Pei P, et al. Experimental studies of wettability control on cylindrical surfacesby elliptical vibration texturing. The International Journal of Advanced ManufacturingTechnology, 2015, 76(9-12): 1807-1817.

[3] Yang Y, Pan Y, Guo P. Structural coloration of metallic surfaces with micro/nano-structuresinduced by elliptical vibration texturing. Applied Surface Science, 2017, 402: 400-409.

[4] Zhu W, Xing Y, Ehmann KF, Ju B. Ultrasonic elliptical vibration texturing of the rake face ofcarbide cutting tools for adhesion reduction. The International Journal of AdvancedManufacturing Technology,2016, 85 (9-12):2669-2679

Applications of Micro Textured Surfaces

Lithography Focused Ion Beams Electron beam machining

Electrical discharge machining Laser machining Elliptical vibration texturing

How to Fabricate Micro Textured Surfaces?

<0.010 m ~ 1 m >100 mSurface Feature Size [m]

Application areas of large-area textured surfaces on

hard materials

Peta Technologies

Required Texturing

Technologies

> 100 m

2~

m2 <

0.01 m2

ConventionalTexturing 

Technologies

TeraTechnologies

GigaTechnologies

Surface Area [m

2]

Future Directions

X-Technology: X = Surface features / m2

Surface Texturing Domain

ProcessesTime 

(per m2)Assumptions

Vibro/ultrasonic ‐machining 1 hour Working at 28 kHz

Laser ablation 115 days Each dimple takes 0.1sMicro‐rolling 50s Rolling speed: 20mm/sMicro‐milling 1.5 years Each dimple takes 0.5s

100 µm diameter dimple array with 100 µm pitch in both directions

Processing Times by Different Texturing Methods

1D VAM: tool is driven in a linear path, which is superimposed on the upfeed motion of the workpiece:

t V

2D VAM: a vertical harmonic motion is added to the horizontal motion of 1D VAM. The tool moves in a tiny circle or ellipse, which is superimposed on the upfeed motion:

t Vt

[1] Brehl, D. E. and Dow, T. A. (2008). Review of vibration‐assisted machining. Precision engineering, 32(3), 153‐172.   

Vibration-assisted Machining - 1D and 2D Motions

Surface Texturing Method

Texture Designs

Workpiece

Piezo Cell

Mounting Plate

Tool Bit

Capacitance Sensor

1D Motions

Prof. Wang

1D Motions

Non-resonant ModeResonant Mode

[1]

1. Moriwaki, T., and Shamoto, E., 1995, "Ultrasonic Elliptical Vibration Cutting," CIRP Annals.

Generation of Simple Sinusoidal Micro-structures

Generation of Controlled Complex Topography

Resonant vs. Non-resonant Mode

Elliptical vibration cutting (EVC ) Elliptical vibration texturing (EVT )

Multi-frequency vibration texturing (MFVT )

• In the cutting direction, the tool’s position relative to the workpiece is given by:

• Then the velocity can be derived:

• EVC: λ≤1• EVT : λ>1• MFVT: Multi-frequency / Arbitrary

trajectories

− sin

=60

Vibration-assisted Texturing Methods

Tangential Mode

Normal Mode

Measured tool vibration trajectories at

the resonant frequency P. Guo et al., “Development of a tertiary motion generator for elliptical

vibration texturing,” Precision Engineering, 2013; 37: 364-371.

Resonant-mode 2D TMG design

Resonant Mode Motion Generators

Influences of the principal overlapping ratio and the minor overlapping ratio

(a) (b) (c)

P. Guo and K. Ehmann, “An analysis of the surface generation mechanics of the elliptical vibration texturing process,” International Journal of Machine Tools and Manufacture, 2013; 64: 85-95.

Micro-Texture Generation

P. Guo et al., “Experimental Studies of Wettability Control on Cylindrical Surfaces by Elliptical Vibration Texturing,” 2014, to be submitted

DOC = 0 µm DOC = 3.5 µm

Depth-of-cutSmooth surface

Example 1: Wettability Control

Process Principle

Cutting velocity

Spacing distance ：d

Cutting velocity

Vibration angular frequency Orientation: Perpendicular to the cutting direction

f = kHz， 10~30mm/s

d~ Visible spectrumPing GuoThe Chinese University of Hong Kong

Example 2: Structural Coloration

Color spectrum on brass surface marked by ten segments: each segment has been textured with different spacing

distances (from 400 nm to 760 nm).

Color Spectrum

Ping GuoThe Chinese University of Hong Kong

Mona Lisa16 levels of color40 x 40 um pixel

Example 2: Structural Coloration

1 2 3 40.0

0.4

0.8

1.2

1.6

2.0

CC IUEVC

1) Thrust force, N, 2) Cutting force, N, 3) Surface roughness Sa, µm and 4) Profile roughness Ra, µm

Numerical comparison between CC and IUEVC methods regarding thrust

force, tangential force, surface roughness and profile

roughness. (vc=5 mm/s, ap=4 µm, fr=10 µm, Rn =200 µm)

Inclined Ultrasonic Elliptical VibrationTexturing (IUEVT)

2D and 3D images of conventional and

UEVT textures

0 100 200 300 400 500 600-12

-10

-8

-6

-4

-2

0

2

4

Prof

ile /µ

m

X /µm

UEVT method non-UEVT method

Profiles and forces

-2 0 2 4 6 8 10 12 14 16 18 20

-2

0

2

4

6

8

10

Cut

ting

forc

e /N

Time /s

non UEVT method UEVT method

UEVT textures

Conventional texture

Comparison of Conventional and UEVT Texturing

Rake face adhesion: (a) non UEVT insert, (b) UEVT insert with a 400 µm pitch, (c) UEVT insert with a 200 µm pitch

Chip morphology: (a) non UEVT insert, (b) UEVT insert with a 400 µm pitch, (c) UEVT insert with a 200 µm pitch

Chip Adhesion and Morphology

TARGET METRICS:(a) Max displacement: 50 m, (b) Max cutting force: 100 N(c) Stiffness: 10 N/m

Non-resonant Motion Generator

(a) one quarter of the CB mechanism, (b) half of the ZFH mechanism CB – Compound bridge

ZFH – Z-shaped flexure hinge

Schematic of the Structural Components

Non-resonant Motion Generator

1st mode 2nd modeFrequency (Hz) 494.4 679.5

Modal Analysis

Frequency=30 Hz, cycle=30, Vp-p=400 V

Vibration Trajectory Analysis

Texturing of Cylindrical Surfaces

Flow Chart of Surface Generation Simulation

Spindle speed Feed rate Depth of cut

21 rmp 40 μm/rev 20 μm

Table. 1 Cutting parameters

Table. 2 Cutter parameters Nose radius Rake angel Clearance

angelIncluded

angle200 μm 10 deg 7 deg 55 deg

Table. 3 Vibration parameters NO. Voltage Phase Frequency

1400 V 60 deg

30 Hz2 10 Hz3 10 Hz+30 Hz

Experimental Conditions

(f=10 Hz, ap=20 μm, n=23 RPM, fz=50 μm/rev) (1.41 mm×1.06 mm)

Experimental result Simulation result

Experimental and Simulation Results

(f=30 Hz, ap=20 μm, n=23 RPM, fz=50 μm/rev) (1.41 mm×1.06 mm)

Experimental result Simulation result

Experimental and Simulation Results

(f=10 +30 Hz, ap=20 μm, n=23 RPM, fz=50 μm/rev) (1.41 mm×1.06 mm)

Experimental result Simulation result

Experimental and Simulation Results

Example: Friction Reduction

(a) 3D measurement of micro-textures in 360º, (b) partial view, (c) theoretically generated surface (1.0

mm×1.0 mm)

Simulation and Experiment

Texturing in Facing Operations

f =30 Hz; n=7 RPM; fz = 250 μm/rev; ap=5 μm

Generated Surface TexturesConstant Frequency

f =30-1 Hz; n=7 RPM; fz = 250 μm/rev; ap=5 μm

Generated Surface TexturesVariable Frequency

f =30-1 Hz; n=7 RPM; fz = 250 μm/revap=0 μm ap=5 μm ap=10 μm ap=20 μm

1.4mm 

Effect of Depth of Cut on Surface Texture

f=30-1 Hz; n=7 RPM; f= 250 μm/rev; ap=5 μm f=45-1.5 Hz; n=7 RPM; f= 250 μm/rev; ap=5 μm

Effect of Frequency on Surface Texture

Resonant mode Vibration frequency: 28 KHz Sigle frequency Vibration amplitude: tangential 8.79 μm

normal 7.28 μm

Non-resonant mode Vibration frequency: 1-494 Hz Multi-frequency Vibration amplitude: tangential ±74.6 μm

normal 90.7 μm

Comparison between Resonant and Non-resonant Methods

• Several methods for surface texturing have been presented alongwith the design of the corresponding devices.

• Methods for 1D and 2D resonant and non-resonant texturing werediscussed.

• The developed surface generation model that predicts surfacetopography is in close agreement with the experimental results.

• Controlled uniform textures can be efficiently fabricated.• Different topographies can be obtained by controlling the depth of

cut, cutting speed, federate, amplitude and frequency ofvibrations.

Conclusion

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